Thought Disorders
Perspective
In the 1800s, Morel introduced the term dementia praecox to describe a progressive deterioration of mental functioning and behavior with onset in adolescence to early adult life.1 In 1911, Bleuler detailed the specifics of this disorder, which he termed schizophrenia, or “split-mindedness.”2 Early treatments of schizophrenia included ice water immersion, barbiturates or insulin to induce prolonged narcosis or coma, seizure induction with pentylenetetrazol, electroconvulsive therapy, and frontal leukotomy.3 The effectiveness of these treatments was marginal at best, and until recent times, most schizophrenic patients were relegated to lifelong institutionalization.
Modern-era pharmacotherapy for schizophrenia, with chlorpromazine and haloperidol, began in the early 1950s. This treatment proved so successful that by the 1960s, most psychiatrists believed that schizophrenia could be successfully managed in the outpatient setting. In 1965, the Community Mental Health Centers Act initiated the release of medicated schizophrenic patients into the community.4 Unfortunately, inadequate family support, unavailability of jobs and low-cost housing, and lack of funding for social services and outpatient psychiatric care left many of these individuals isolated without the tools needed for resocialization. Currently 20 to 40% of homeless people in the United States have a major mental illness.5 Emergency departments frequently serve as the primary entry point into the mental health care system for many of these individuals.6
Principles of Disease
The etiology of schizophrenia is currently believed to be heterogeneous from interaction of biologic and environmental factors. Studies involving adopted twins whose biologic parents have schizophrenia demonstrate a strong genetic basis for the disorder. Although the overall incidence of schizophrenia in the general population is roughly 1%, it is approximately 10% in first-degree biologic relatives of individuals with the disorder.7 With regard to the pathophysiologic mechanism of schizophrenia, dopaminergic, serotonergic, cholinergic, and glutamatergic systems have been implicated.8–11
Schizophrenia is also postulated to be a neurodevelopmental disorder resulting from the influence of environmental factors on genetically predisposed individuals. Disruptions in fetal brain development, caused by perinatal hypoxia, poor nutrition, infection, and other insults, may set the stage for subsequent development of schizophrenia.1,12 New imaging techniques have documented structural brain abnormalities, most of which appear to be developmental rather than degenerative in nature.8 Evidence supports the existence of a progressive continuum of psychotic illness, beginning with unipolar depression and progressing to bipolar illness, schizoaffective psychoses, and finally schizophrenia.1,13,14
Clinical Features
Overt signs of schizophrenia usually become manifested during adolescence or early adult life. Many patients describe a childhood with few interpersonal relationships and a withdrawn, eccentric personality.
Phases of Schizophrenia
The development of schizophrenia involves three phases.15 The premorbid phase is characterized by the development of “negative” symptoms with deterioration in personal, social, and intellectual functioning. Patients progressively withdraw from social interactions and neglect personal appearance and hygiene, which negatively affects their work, school, and home life.
In the residual phase, patients are left with impaired social and cognitive ability, marked by bizarre ideation, delusions, peculiar behavior, poor personal hygiene, and social isolation. Most schizophrenic patients require a sheltered environment to function adequately. Despite a wide spectrum of severity, the general course for most patients is one of gradual deterioration with periodic episodes of psychotic decompensation.
Criteria for Schizophrenia
The diagnostic criteria for schizophrenia (Box 110-1) are outlined in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR).15
• The patient must exhibit two or more of the following symptoms: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms (such as flattening of affect, poverty of speech, or inability to perform goal-directed activities).
• There must be a sharp deterioration from the patient’s prior level of functioning (work, school, self-care, or interpersonal relations), and there must be continuous signs of disturbance for at least 6 months.
• The diagnoses of schizoaffective and mood disorders with psychotic features must be excluded.
• In evaluating these patients, emergency physicians must exclude myriad medical conditions that can mimic or cause psychotic symptoms.
Delusions
The DSM-IV-TR defines delusions as “erroneous beliefs that usually involve a misinterpretation of perceptions or experiences.”15 The delusions seen with schizophrenia are most often persecutory, religious, or somatic.
Hallucinations
A hallucination is a sensory experience that exists only in the mind of the person experiencing it. Hallucinations associated with schizophrenia may be auditory, visual, olfactory, gustatory, or tactile. Auditory hallucinations (hearing voices) that are pejorative or threatening are especially common.
Disorganized Speech
Patients with schizophrenia experience loosening of associations, with thoughts shifting randomly from one topic to another without a logical connection. Their speech often shows lack of content. Neologisms (nonsense words invented by the patient) and perseverations (frequently repeated words or phrases) are common. On occasion, the patient’s speech may be so severely disorganized that it is totally incoherent, termed word salad.
Grossly Disorganized or Catatonic Behavior
Schizophrenic patients have difficulty in formulating and producing goal-directed behavior. They are often found wandering about, disheveled, malnourished, talking to themselves, and exhibiting unpredictable agitation. It is this behavior that usually prompts family members, friends, or the police to bring them to the emergency department. Patients exhibiting catatonia appear to be completely unaware of their environment, maintain a rigid posture, and resist efforts to be moved.
Negative Symptoms
Three negative symptoms—flattening of affect, alogia, and avolition—account for a significant degree of the morbidity associated with schizophrenia. Patients with a flattened affect exhibit little facial expressiveness, eye contact, or body language. Alogia, or poverty of speech, is manifested by brief, laconic, empty replies to questioning. Avolition is characterized by an inability to initiate and to persist in goal-directed activities. Caution should be used in evoking negative symptoms to support a diagnosis of schizophrenia because similar symptoms may be found in patients with severe depression, chronic environmental understimulation, and treatment with neuroleptic medications.
Diagnostic Strategies
Patients with Known Psychiatric Disorders
Patients with previously diagnosed thought disorders who present with mild to moderate exacerbation of their symptoms do not require extensive laboratory evaluation.16 Because some of these patients may have coexisting substance abuse or undiagnosed medical disorders, a thorough history, detailed physical examination, and routine toxicology studies are indicated for most patients.17–19 Patients exhibiting severe exacerbation of symptoms accompanied by marked agitation, violent behavior, or significantly abnormal vital signs should undergo more extensive evaluation.
Patients without Known Psychiatric Disorders
Many toxicologic and medical disorders can mimic schizophrenia. Patients with the apparent new onset of psychosis should receive a medical evaluation to exclude toxicologic and medical disorders.20–23 Both the DSM-IV-TR and review articles on this topic emphasize that most toxicologic and medical causes of altered mental status that simulate acute schizophrenia are best recognized by patterns of presentation combined with focused testing based on one’s index of suspicion for nonpsychiatric disease, rather than the reliance on a broad use of screening tests.
Differential Considerations
Certain medications and medical disorders may affect thought processes, causing patients to exhibit abnormal behavior (Boxes 110-2 and 110-3). This behavior may range from mild personality changes to apparent acute psychosis, even in the absence of an underlying psychiatric disorder.1 Factors that should alert one to a medical disorder include the following: history of substance abuse or a medical disorder requiring medication; patient’s age older than 35 years without previous evidence of psychiatric disease; recent fluctuation in behavioral symptoms; hallucinations that are primarily visual in nature; presence of lethargy; abnormal vital signs; and poor performance on cognitive function testing, particularly orientation to time, place, and person. These and other factors may be helpful in differentiating functional (psychiatric) from organic (medical) causes of abnormal behavior and can be easily recalled with the mnemonic MADFOCS (Table 110-1).24
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